Answers: 0. carries signals to the brain to be interpreted as sound 1. blurry vision caused by an unevenly curved cornea or lens 2. carries messages from the eye to the brain 3. able to see things nearby, but far away things are blurry 4. where light enters the eye 5. substance composed mostly of bacteria that builds up on teeth 6. oil released by the oil (sebacious) gland 7. invisible energy waves given off by the sun 8. a unit used to measure the loudness of sound 9. the part of the skin that contains the root of a hair 10. able to see things far away, but things nearby are blurry 11. straightening crooked teeth 12. a mineral that can help protect teeth 13. clear covering that protects the eye 14. controls that amount of light that enters the eye 15. gum disease